Just a guess: but with the change to the Pro-HD, are you now attempting to sling shows in HD format where before you were slinging in SD format? Since HD requires so much more data, could your ISP be now throttling you because you are exceding some data transfer limit over time that they have in place?
I can definitely understand your frustration with the speed issues your having. I would recommend giving our customer support a call. I am sure that one of our awesome agents will be able to assist you in getting this resolved.
The above link explains how to get in touch with our support anywhere in the world.
Hope this helps and thanks for using our Answers Forum.
Sling Media Moderation Team